Even folks with Ph.D's and lots of familiarity with experiential learning can be skittish about using rubrics to make sense of authentic artifacts of reflective learning. This explanation is the simplest and clearest we've yet seen about how to code qualitative data.  Using a rubric is a type of deductive coding, so, to get more comfortable with it, all you really need to read is the part of this essay on "Deductive Coding 101."  But the advice on keeping things simple is excellent, too.